Work-presenting mechanism for blindstitch sewing machines



Aug. 27, 1929. c. w. MUELLER WORK PRESENTING MECHANISM FOR BLIND STITCHSEWING MACHINES Filed June 25, 1928 immnl Patented Aug. 27, 1929.

UNITED STATES v PATENT OFFICE.

7 CHARLES WPMUELLER, or ST. LOUIS, MISSOURI, Assrerion To LEwIsINvIsrBLns'rrron MACHINE COMPANY, on ST. LOUIS, MISSOURI, A CORPORATION or MAINE.

wonx-ransnnrme MECHANISM FOR BLINDS'IITCH SEWING MACHINES.

Application filed June 23,

This invention relates to new and useful improvements in blind stitchsewing machines, although the invention is more particularly directedto' the work, presenting mechanism thereof. v

The invention is especially adapted for. use in felling operationsgenerally, and the invention has among its several objects to. providean oscillatory ridge forming disc which is bodily raised and loweredduring each complete reciprocation whereby a ridge of material will beformed by the disc during" its forward traveland whereby thedisc will belowered from its engagement with the ridge during the'backward travelofthe disc, and to provide yieldable meansfor cooperation with thedisc tomaintain the ridge of material taut during the forward travel Fig. 1 isa top plan View of a presser foot constructed in accordance withmyinvention and showing the relation between the foot, the material, theridge forming disc, the yieldable fingers which cooperate with thematerial and disc, and the needle. Fig. 2 is a' bottom plan viewof the.foot, Fig. 3 is a longitudinal sectional view taken through the feedopening in the foot and showing particularly therelation ofthe disc, thepresser foot, the yieldablefingers, the top feed and the needle, and vFig. 1 is a cross sectional view takenon the line 4-4 of Fig. 1. V

Like reference numerals designate corresponding parts throughout theseveral figures of'the drawings. I

Referring to the accompanying drawings, my invention comprises a workpresenting mechanism for blindstitch sewin machines which includesa-presser foot '3, a work clamp B, a lower feeding mechanism C, a topfeeding mechanism D, anda' needle E. The presser foot A is constructedto be fixedly secured at itsrear end to the sewing machine head. Thisfoot includes a of the disc whereby the material will he held,

1928. Serial a... 287,756.

main portion 5 having a centrally located and rearwardly extending slot6 formed there1n. Extending upwardly from the foot on opposite sides oftheslot 6 is a pair of ears 7, 7 to which arms '8, 8 are adapted to berespectively. attached. These arms 8, 8 are adapted to be adjustablyattached at them upper ends to the sewing'machine 'head so as to varythehorizontal plane of the foot. Formed onth'e upper face of the foot andextending upwardly therefrom are aligned needle guides 9, 1O andllsrespectively. These guides extend in a plane at right angles to thelongitudinal axis of the slot 6, the guides 9 and 10being on the leftside oftheslot andtheguide 11 bein on the right side of the slot. Theguide 9 and the guide 11 are respectivelyformed w th upstanding walls 9and 11, said walls being disposed in alignment and arranged on the frontside of theguides. The end of the guide 11 adjacent the slot 6 is formedwith a recess 12 to receive the point of the needle during itspenetrating stroke in order to prevent the point of said needle fromspringing downwardly during the contlnued' penetrating stroke thereof.

DISPOSGdbQlOW the presser foot is a work support 13 and mounted on thiswork support for oscillation about an axis 14 is a combined ridgeforming and work feeding disc 15. This discis supported for bodilyvertical movementsduring each reciprocating stroke thereof. The axis 14is disposed directly below the path of needle reciprocation and inparallelism therewith whereby the disc 15 will oscillate in the slot 6of the presser foot.

The disc 15 is provided along its upper edge with a plurality of teeth16 and along its lower edge with front and rear concentric portions 17and 18' of different radii, and with an'eccentric or stepped portion 19intermediate the concentric portions The disc 15 is supported during itsoscillations bya roller 20'w'hich directly engages theconcentricperipheral portions 17 and 18 and the eccentric or steppedportion 19 of the disc whereby upon" each oscillatory stroke the discwillbe bodily raised and lowered. In the position of the disc as shownin Fig. 3, said disc is at the upper end of its movement and at theextreme feeding end of its stroke. It will be observed-that when thedisc is i on opposite sides of the disc. -T'hese guides further serve toprevent the needle from beoscillated rearwardly, said discwill belowered by reason of the eccentric or stepped portion 19.

The means of mounting the disc 15 and the means for oscillating the sameis fully In the operationof my invention aslthus far described,the'material to be stitched is positioned between the foot A; and theclamp -B,, and the disc is; then moved fearwarl'dly and upwardly totheposition shown Fig. J 3, thereby forming a ridge'fofmaterialf andfeeding the material a stitch lengthdistance. The needle D is thenoscillated on its needle penetrating stroke and conseqnntly the material will be penetrated by the needle while the material is in a stateofv rest. The disc is then oscillated in the opposite direction andduring. the first portion of this oscillation the needle remains in thematerial. This backward oscillation of the disc has a tendency to dragthe material towards the front of the machine, or in otherizwords, withthe disc. At this time, however; the needle is in the material, andconsequently the mate'rial is heldiagainst being draggedfby the discthrough the medium of the" walls 9 and 11 of the needle guides which aredisposed ing sprung duringthe *firstpart of'-the backward movement ofthe disc.- As soon asthe disc reaches the eccentric or stepped portion19, said disc is lowered and the needle is withdrawn from the material.

In order to hold the ridge; of material against the thrust of the needleduring the penetrating stroke of the latter,: I have provided thepresser foot with a pair of spring fingers 21, 21 which areulocated onopposite sides of the disc 15 and are pivoted at their forward ends byscrews 22,122 to the upper face of the main portion 5 of the presserfoot at points in "advance of said'disc, the fingers extendingrea'rwardly to a point beyond the line ofneedle reciprocation. The finers 21, 21 are in the nature of levers, the pivots 22,

" 22 beingthe fulcra thereof, The-forward ends of the fingers 21constitute short lever arms 23, 23 and disposed between these lever armsis a coil-spring 24 which normally urges the rear arms 25,25 intofrictional and sliding contact with the material on opposite horizontalportions from which are "movable :in recesses 26', '26' formed -in-thunder face sides of the dise'1'5.

the levers are bent downwardly from the pivots 22 and thence rjearwardlyto form of the'mai'n'portion Hof-thdpresetffoot on opposite sides of theslot 6, the under faces The rear arms-25 of thereofbeing flush with theunderface of the foot in order to give an uninterrupted surface to said"foot. The spring fingers 21 are each formed with an upwardly extending'sulres snflicient play of the fingers to accommodate materials ofgreatly varying thicknesses.p"," ,1

Normally the' rear arms 25, 25 are held in spaced relation by the stoplugs 27 a distance sufiicien-t to permit the disc 15 during its forwardand upwardv movement toxprioject a node or ridge of material into theslot 6, the movement forcing-the rear-arms 25, 25 outwardly against thetension of the spring 24. This frictional engagement between the arms25', 25' and the material serves to retain the material while in itsridge formation against the thrust of the needle penetration, andpermits the disc to be readily lowered during the latter part of itsretnrnstroke.- i

It is of course to be understood that the details of structure andarrangements of parts maybe variously changed and modified withoutdeparting from the spirit and scope of my invention;

I claim! g 1. In a'sewing machine, the combination with a' stitchforming mechanism including a reciprocatory needle, of a slotted presserfoot, a work support, a toothed ridge forming and fabric feedingdiscsupported foroscillations on saidzwork support and located in the planeof the slot in the foot, the path of needle'reciprocations' being in aplane crossing the plane of the disc, means for oscillating said disc, apair of fabric engaging levers fulcrumed on the foot for cooperationwiththe fabric on opposite sides gaging levers fulcrumed-on the footfront 'of'the needlefor cooperation wlthv the fabjricon opposite sidesof the-disc, and means for yield ably retaining thefingers in contactwith the fabric. I I I 3. In a sewing machine, the combination with astitch forming mechanism including a reciprocatory needle, of a slottedpresser foot, a work support, a toothed ridge forming and fabric feedingdisc supported for oscillations on said work support and located in theplane of the slot in the foot, the path of needle reciprocations beingin a plane crossing the plane of the disc. means for oscillating saiddisc, a pair of fabric engaging levers fulcrumed on the foot for 00013-'eration with the fabric on opposite sides of the disc, and a singlespring for yieldably retaining the fingers in contact with the fabric.

4. In a sewing machine, the combination with a stitch forming mechanismincluding a reciprocatory needle, of a slotted pressure foot, a worksupport, a toothed ridge forming and fabric feeding disc supported foroscillations on said work support and located in the plane of the slotin the foot, the path of needle reciprocations being in a plane crossingthe plane of the disc, means for oscillating said disc, a pair of fabricengaging levers fulcrumed on the foot in front of the needle forcooperation with the fabric on opposite sides of the disc, and a singlespring for yieldably retaining the fingers in contact with the fabric.

5. In a sewing machine, the combination with a stitch forming mechanismincluding a reciprocatory needle, of a slotted pressure foot, a worksupport, a toothed ridge form ing and fabric feeding disc supported foroscillations on said work support and located in the plane of the slotin the foot, the path of needle reciprocations being in a plane crossingthe plane of the disc, means for oscillating said disc, a pair of fabricengaging levers fulcrumed on the foot for cooperation with the fabric onopposite sides of the disc, said foot being formedwith openings onopposite sides of the slot, means for yieldably retaining the fingers incontact with the fabric, and stop lugs respectively carried by thefingers for cooperation with the walls of the openings of the foot tolimit the inward movements of the fingers.

6. In a sewing machine, the combination with a stitch forming mechanismincluding a reciprocatory needle, of a slotted pressure foot, a worksupport, a toothed ridge forming and fabric feeding disc supported foroscillations on said work support and located in the plane of the slotin the foot, the path of needle reciprocations being in a plane crossingthe plane of the disc, means for oscillating said disc, a pair of fabricengaging finger levers fulcrumed on the upper face of the foot in frontof the needle, the levers extending downwardly and rearwardly into theslot of the foot and terminating in rear of the path of needlereciprocation, and means for yieldably retaining the fingers in contactwith the fabric.

7 In a sewing machine, the combination with a stitch forming mechanismincluding a reciprocatory needle, of a slotted pressure foot, a worksupport, a toothed ridge forming and fabric feeding disc supported foroscillations on said work support and located in the plane of the slotin the foot, the path of needle reciprocations being in a plane crossingthe plane of thedisc, means for oscillating said disc, a pair of fabricengaging finger levers fulcrumed on the upper face of the foot in frontof the needle, the rear arms of the levers extending downwardly andrearwardly into the slot of the foot and terminating in rear of the pathof needle reciprocation, and a single sprin disposed between the frontarms of the ger levers for yieldably retaining the fingers in contactwith the fabric.

8. In a sewing machine, the combination a reciprocatory needle, of aslotted pressure foot, a work sup ort, a toothed ridge forming andfabric eeding disc supported for oscillations on said work support andlocated in the plane of the slot in the foot, the path of needlereciprocations being in a plane crossing the plane of the disc, saiddisc. support including aperipheral cam on the lower edge of the disc, aroller journaled on the work support and in direct contact with thedisc, means for oscillating said disc whereb the same will be bodilyraised and lowere through said cam and roller during the respectiveforward and backward oscil- 100 lating movements thereof, and needleguides on the foot on opposite sides of the slot to retain the needleagainst springing during the backward oscillation of the disc.

signature.

CHARLES W. MUELLER.

with a stitch forming mechanism including

